More particularly, the embodiment of the present invention relate to a valve assembly forming all or part of a gas dispensing device in a gas lighter suitable notably for lighting a cigarette. Such a gas lighter comprises a reservoir having an upper wall through which there passes a well and intended to contain a fuel, the valve assembly being arranged in the well. The valve assembly comprises a hollow rod that may form a spray nozzle and a tubular rigid body housing the lower end of the hollow rod. The tubular body may be typically a metallic body but rigid plastic may be used as well, as disclosed in patent application CA 893226. The hollow rod can be engaged by an actuator, for instance a lever, and is movable between a closed position and an opened position enabling gas to flow through the well from inside of the reservoir to the ignition area.
To prevent gas leak through the well, outer sealing is required between the tubular rigid body and the well, while inner sealing is required between the tubular rigid body and the hollow rod. It is a known practice to provide a cylindrical washer for retaining the hollow rod as depicted in FIG. 1 of document U.S. Pat. No. 4,478,570. Such a washer, which is preferably less rigid than the hollow rod, is adapted to prevent leaks of gas from the space surrounding the lower end of the hollow rod. Indeed, the sliding area between the hollow rod and the tubular rigid body cannot be considered as gas tight.
However, sliding movement of the hollow rod through the washer may cause loss of tightness and a secondary flow of gas when the valve is opened. It is also known valve units that comprise several sealing joints for improving the seal function, resulting in numerous individual parts in the valve assembly. These valve units for gas lighters are relatively expensive to produce, because of the time necessary for assembly of these parts, which are of very small dimensions. This high cost of the valve units is particularly unwelcome in the case of cheap lighters, such as those which are thrown away after the fuel stored therein has become exhausted.
Therefore, a need exists for a gas lighter valve assembly of simplified construction, preferably reduced bulk, while at the same time affording a good seal and safety of use.